<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>

<body>

</body>
<script>
    let a = [1, 2, 3, 4, 5];
    let b = [1, [2, 3],
        [4, [5, 6]]
    ];
    console.log(a.toString());
    console.log(typeof a.toString());
    console.log(b.toString());
    console.log(typeof b.toString());


    var s = a.join("*"); //指定分隔符
    var s1 = a.join('');
    console.log(s); //返回字符串“1*2*3*4*5”
    console.log(s1); //返回字符串"12345"
    console.log(typeof s.toString());
    console.log(typeof s1.toString());

    var s = "1==2== 3==4 ==5";
    var sa = s.split("==");
    console.log(sa);
    console.log(sa.constructor == Array);
</script>

</html>